I recently read the accident report on BEA 548, but I'm unsure of some technical terms used on p. 4 of the report (p. 14 of the linked PDF):

Apart from the probability that in the particular conditions he would have elected to handle the aircraft himself, an examination of the lamp filaments in the P1 'azimuth' window showed that at the time of the crash the compass switch was turned to port, thus indicating that P1 was flying.

My question is: What are the "azimuth window" and "compass switch" in this context? Was the HSA Trident equipped with some sort of flight control transfer system between the P1 (captain) and P2 (flight officer) seats?


1 Answer 1


They are autopilot controls are visible in this clip from the Wikipedia cockpit picture:

Trident controls

Source: Wikipedia

Airliner avionics have independent left and right systems for the captain and first officer. But, in many aircraft, there's only one autopilot. It's not a critical system and the crew can hand fly the plane.

The autopilot controls allow it to be set to receive data from either side. Standard procedure is for it to be set to the side of the pilot flying so it follows what the pilot flying sees. The pilot not flying can monitor the flight on their displays and detect any deviations.

Note the switch at bottom center with the option to select Port or Stbd.


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